Question #N832

A circle with radius 5 has its center at (4, -2). Which of the following is an equation of this circle?
A. (x + 4)^2 + (y - 2)^2 = 5
B. (x + 4)^2 + (y - 2)^2 = 25
C. (x - 4)^2 + (y + 2)^2 = 5
D. (x - 4)^2 + (y + 2)^2 = 25

Correct Answer is: D

The standard form of the equation of a circle is (x - h)^2 + (y - k)^2 = r^2, where (h, k) is the center of the circle and r is the radius of the circle. Since the center of the circle is (4, -2) and the radius is 5, the equation of the circle is (x - 4)^2 + (y - (-2))^2 = 5^2, or (x - 4)^2 + (y + 2)^2 = 25.